Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
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Sekhar Udaya Nagothu M. Muralidhar M. Kumaran B. Muniyandi R. Umesh K.S. Krishna Prasad Sena S. De SilvaAbstract
Approximately 70% of shrimp consumed globally is farmed. India is ranked among the top five shrimp farming countries globally, and occurs mainly in the eastern coastal state of Andhra Pradesh (AP). More than 90% of the farms are less than 2 ha and are farmer owned, operated and managed. The objective of this study was to increase our understanding of climatic and socio-economic factors influencing this sector, through a survey of 300 shrimp farmers in AP in 2009/10. The farming communities were divisible into two groups: members of a society/cooperative and those operating individually. The latter were large scale adopting more intensive practices. The average production cost was Indian Rupees (IRS) 80,186 ha-1 and net income in summer and winter was IRS 221,901 and IRS 141,715, respectively. The mean technical efficiency estimated using Stochastic frontier function was 7% and 54%. The present study attempts to explain the difference in efficiencies using socio-economic and climatic variables, the latter being a novel approach. Among socio-economic variables, farming experience and membership in society were found to have a significant influence to improve technical and economic efficiencies. Further improvements in identifiable facets of the practices and a consequent increase in technical efficiency will make the sector less vulnerable to climatic change impacts.
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This Technical brief is a short summary of the results obtained from the field trials conducted at Agro Climate Research Centre, Tamil Nadu Agricultural University, India to understand the Pest dynamics at elevated temperature. Among the major food crops, rice (Oryza sativa L.) forms the stable food for more than half of the world’s population. Among various constrains in rice production, losses due to pest is a major concern. Climate change resulting in increased temperature could impact crop insect pest populations in several complex ways. Although some climate change temperature effects might tend to depress insect populations, most researchers seem to agree that warmer temperatures in temperate climates will result in more types and higher populations of insects. Hence, it is important to understand the population growth of the important insect pests such as yellow stem borer (Scirpophaga incertulas) and brown planthopper (Nilaparvata lugens) of rice. The results revealed that there was an inverse correlation between temperature and total life span, developmental time and also fecundity. However there was a positive correlation between temperature and net reproductive rate and development rate.
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This Technical brief is a short summary of the results obtained from the field trials conducted at Anbil Dharmalingam Agricultural College and Research Institute, Trichy, India during Rabi (2010-2011) to evaluate the role of photosynthetic diazotrophs in reducing methane flux from rice soil ecosystem as a part of climarice project. Global warming induced by increasing concentration of greenhouse gases (GHGs) in the atmosphere is a matter of great environmental concern. Methane, carbon dioxide, nitrous oxide and chlorofluorocarbon are the GHGs which have strong infrared absorption bands and trap part of the thermal radiation from the earth surface. Rice fields have to be considered as a significant source of greenhouse gases and rice field eco systems account for about 60 Tg methane per year or about 12 per cent of the global annual methane emission. The purpose of this study is to explore the potential of blue green algae and azolla in minimizing methane flux at source in paddy field ecosystem. In the present study, combined application of organics and blue green algae not only recorded higher yield, but also found to emit less methane in paddy cultivation than the application of organics alone.
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Farmers attempt to develop a different environment for rice under System of Rice Intensification (SRI) method by which the rice plants can exhibit their full potential. Major principles of SRI includes perfect land levelling, lower seed rate, transplanting young seedlings of 12 days old, single seedling / hill with wider spacing (25 x 25 cm), careful water management (applying a minimum of water during vegetative growth and at later stages maintaining only one inch water) and weed management using cono weeder thrice in the vegetative stage. Researchers and farmers’ experience in the Cauvery basin in Tamil Nadu from ClimaRice have shown that yields of rice could be increased considerably (18–27%) with reduced water consumption (22- 25%) and less expenditure, just by following SRI method of cultivation. Thus it is beneficial for small and marginal farmers under changing climatic conditions.